I agree with sekio and disagree with the above 2 posters.
Opiates are awesome for anytype of comedown, and on the tail end of a long acid trip, it's just what the doctor ordered.
That being said, seriously though, it's not a brain trust idea to cut lsd with codiene, it just sounds silly. I've noticed for myself, opiates are a waste during a trip for the most part because the lsd is such a more overpowering substance. Anytime you trip it changes your perception of "reality", and that's a very core feeling.
...really though, codeine and lsd dosed at the same time? I dunno...what dealer/chemist does that?